Shader Story

Common HLSL Functions: Distance

distance(a, b) returns the Euclidean distance between two points a and b. It’s useful for radial falloffs, circular masks, ripples, and proximity-based effects.

float d = distance(float3(0.0, 0.0, 0.0), float3(1.0, 1.0, 1.0));

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Visual demo

This shader visualizes how distance() calculates the separation between world-space positions and a given center point. The result is a smooth radial gradient, often used in glow masks, area effects, and procedural transitions.

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URP Shader Code

Shader "DecompiledArt/CommonFunctions/Distance/Distance"
{
    Properties
    {
        _Pos_X("Pos_X", Range(-10.0, 10.0)) = 0.0
        _Pos_Y("Pos_Y", Range(-10.0, 10.0)) = 0.0
        _Pos_Z("Pos_Z", Range(-10.0, 10.0)) = 0.0
        _Contrast("Contrast", Range(0.01, 8.0)) = 1.0
    }

    SubShader
    {
        Tags { "RenderType" = "Opaque" "RenderPipeline" = "UniversalPipeline" }

        Pass
        {
            HLSLPROGRAM
            #pragma vertex vert
            #pragma fragment frag

            #include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Core.hlsl"

            struct Attributes
            {
                float4 positionOS : POSITION;
            };

            struct Varyings
            {
                float4 positionHCS : SV_POSITION;
                float3 positionWS : TEXCOORD0;
            };

            CBUFFER_START(UnityPerMaterial)
            half _Pos_X;
            half _Pos_Y;
            half _Pos_Z;
            half _Contrast;
            CBUFFER_END

            Varyings vert(Attributes IN)
            {
                Varyings OUT;

                OUT.positionHCS = TransformObjectToHClip(IN.positionOS.xyz);
                OUT.positionWS = TransformObjectToWorld(IN.positionOS.xyz);

                return OUT;
            }

            half4 frag(Varyings IN) : SV_Target
            {
                half3 pos = half3(_Pos_X, _Pos_Y, _Pos_Z);
                half col_output = pow((1 - saturate(distance(pos, IN.positionWS.xyz))), _Contrast);
                

                return half4(col_output.xxx, 1.0);

            }

            ENDHLSL
        }
    }
}

URP Shader graph

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🔗 Related Functions

Length • Normalize • Smoothstep • Dot

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